I hope Malone is ok, my dogs are SERIOUS chewers too!! The black kong is supposed to be stronger, we have one of each. My dogs love the nylabones though, they don't usually ruin those right away
I bought these things called rhino bones--they're made by nylabone, and they're rubber---they're actually very strong--haven't been punctured yet!!
They also love big spoons (like the kind you make pasta or whatever with)--Kito used to steal them if I dropped them, so I just let him have a couple--they're pretty tough too!!
If all else fails, I give them some ice cubes, sometimes that soothes their need to chew for a while, and is totally harmless.

Good luck at the Vet tomorrow--let us know what happens!!